1. Field
This patent specification describes a method and device for controlling PC cards used for a personal computer and a passive-card-adapting card, and more particularly to a method and device for controlling different types of PC cards used for the personal computer without changing a control program of a host computer of the personal computer and a passive-card-adapting card for a new PC card.
2. Discussion of the Background
A mobile terminal device or a personal computer such as a notebook or laptop computer typically includes a PC card control apparatus which is compliant with the PCMCIA (Personal Computer Memory Card International Association) standard. The PC card control apparatus supports data reading and writing of an existing PC card having a size of a business card. In recent years, mobile terminal devices have been downsized and a new card employing an efficient bus interface such as USB2.0 and PCIexpress has been produced. As a result, a new card control apparatus has been proposed for supporting data reading and writing of the new card.
The PC card control apparatus for the existing PC card has widely been used and it seems a transition of use from the existing PC card to the new PC card may take some time. Until the new PC card completely takes over the existing PC card, the existing PC card and the new PC card may be required to coexist. During the above-described time period, a PC card controlling system which can adapt to both of the existing PC card and the new PC card is needed.
In order to distinguish types of PC cards, hereinafter, the existing PC card is referred to as a “PCMCIA card” and the new PC card is referred to as a “non-PCMCIA card” in the present patent specification.
Some conventional PC card controlling systems have been proposed. One of the conventional PC card controlling systems includes a PC card control apparatus for controlling the non-PCMCIA card in addition to another PC card control apparatus for controlling the PCMCIA card. This configuration of a conventional PC card controlling system requires the terminal device to mount two different card connectors and the PC card controlling system may not be reduced in size.
Instead of having the two PC card control apparatuses, another conventional PC card controlling system supports a PCMCIA active card-adapting card which completely converts functions of the non-PCMCIA card to functions of the PCMCIA card, and converts a power supply level of the non-PCMCIA card to the PCMCIA card, if necessary. This configuration, however, forces a user to carry the non-PCMCIA card and the large and heavy PCMCIA active card-adapting card, which is inconvenient for the user.
There is another conventional PC card controlling system which includes a PC card control apparatus and supports a PCMCIA passive-card-adapting card. The PC card control apparatus recognizes insertion of the non-PCMCIA card and connects the inserted non-PCMCIA card to a controller for the non-PCMCIA card. The PCMCIA passive-card-adapting card is compact and light weight and requires a change of signal wiring to convert a signal pin assignment of the non-PCMCIA card to that of the corresponding PCMCIA card.
Referring to FIG. 1, a structure of a conventional computer system 10 utilizing a PCMCIA passive-card-adapting card 21 is described. The computer system 10 includes a PC card control apparatus 11 and a chipset 12 connected to each other.
The PC card control apparatus 11 is an extension board having a PC card connector 13 and includes a PC card detector 14, a MUX (multiplexer) 15, a PCMCIA controller 16 and a USB (universal serial bus) host controller 17.
The chipset 12 is mounted on a mother board having a PCI (peripheral components interconnect) bus card socket (not shown) for connecting the PC card control apparatus 11. The chipset 12 supports a CPU (central processing unit) (not shown), a memory (not shown) and a USB host controller 18.
The PC card connector 13 is connected with signal lines which respectively correspond to the PC card detector 14 and the multiplexer 15 and communicates with the PCMCIA passive-card-adapting card 21 compliant with the PCMCIA standard. The PCMCIA passive-card-adapting card 21 includes a non-PCMCIA card connector 22 for a non-PCMCIA card 23 and a connecting portion (not shown) to be connected to the PC card connector 13 of the PC card control apparatus 11 installed in the computer system 10. The PCMCIA passive-card-adapting card 21 converts a signal pin assignment of the non-PCMCIA card 23 to that of a PCMCIA card (not shown).
The PC card detector 14 determines whether a card attached to the PCMCIA card connector 13 is a PCMCIA card or the non-PCMCIA card 23 connected via the PCMCIA passive-card-adapting card 21. When the card is determined to be a PCMCIA card, the PC card detector 14 selects a PC CardBus B1 to connect the MUX 15 and the PCMCIA controller 16. When the card is determined to be the non-PCMCIA card 23, the PC card detector 14 selects a USB B2 to connect the MUX 15 and the USB host controller 17.
The MUX 15 receives a signal indicating a type of the inserted card from the PC card detector 14 and forwards the signal to the PCMCIA controller 16 or the USB host controller 17 according to the type of the inserted PC card.
The PCMCIA controller 16 receives the signal from the MUX 15 via the PC CardBus B1 when the PCMCIA card is attached to the PCMCIA card connector 13.
The USB host controller 17 receives the signal from the MUX 15 via the USB B2 when the PCMCIA passive-card-adapting card 21 is attached to the PCMCIA card connector 13. The computer system 10 also has the USB host controller 18 embedded in the chipset 12. However, the PC card control apparatus 11 communicates with the chipset 12 via a PCI bus B3 and the USB host controller 17 is required to convert a data format of the non-PCMCIA card 23 from a format for the USB to a format for the PCI bus.
As described above, the PC card control apparatus 11 is utilized during the transition period of completely replacing the PCMCIA card to the non-PCMCIA card 23. For production, the PC card control apparatus 11 is required to have a simpler structure. Additionally, a host CPU controlling the PC card control apparatus 11, that is, the CPU supported by the chipset 12 in the present patent specification can perform a card controlling operation without changing a control program for the card controlling operation. Further, it is preferable that the PC card control apparatus 11 utilized during the transition period can be flexibly applied to a non-PCMCIA card other than the non-PCMCIA card 23 when it is produced.
There is another conventional PC card control apparatus interfacing data via a PCI bus included in the personal computer and data via a PC CardBus included in the PC card in a pass through mode. The conventional PC card control apparatus serves as a bus bridge provided between a primary side bus (the PCI bus) to which a user cannot directly have an access and a secondary bus (the PCMCIA bus) to which the user can directly have an access. With the pass through mode, a transaction performed on the primary bus can be examined without passing the bus bridge in a manner of no destruction.
The PC card control apparatus 11 of FIG. 1 needs to include the MUX 15 and the USB host controller 18 for converting the data format for the USB to the data format for the PCI bus. Therefore, the circuitry becomes large and complicated.
A power is supplied to the PCMCIA card under a control of the host CPU, that is, under a control of the CPU supported by the chipset 12 mounted on the mother board. The PCMCIA card is activated with a power supply voltage of approximately 3.3V and the non-PCMCIA card 22 is activated with a power supply voltage of approximately 1.5V in addition to that of approximately 3.3V. In order to accept another card activated with a different power supply voltage, the computer system 10 needs to additionally include a new power source and a control program for controlling the new power source, which increases the cost for running the computer system 10.
Further, the PC card control apparatus 11 uses the MUX 15 for switching the PC CardBus B1 and the USB B2. However, the MUX 15 cannot be used for a USB2.0 bus interface which is based on a new standard with a small amplitude of an activating signal.